Gas exchange measurements in neonates treated with extracorporeal membrane oxygenation

Closed-circuit spirometry techniques were used to study gas exchange (oxygen and carbon dioxide transport) across the native lung and membrane lung in ten neonates treated with extracorporeal membrane oxygenation (ECMO). Initially there was negligible oxygen transport across the native lung (0.4 +/- 0.4 mL/kg/min). An increase in native lung oxygen transport (2.0 +/- 1.5 mL/kg/min) at low ventilator settings and high levels of extracorporeal support heralded recovery of the native lung and predicted weaning from ECMO. Measurement of oxygen consumption and carbon dioxide production permitted the energy expenditure to be calculated in these critically ill neonates. The metabolic rates varied widely in each neonate over time and among neonates. (mean 57 +/- 11 kcal/kg/d, range 38 to 80 kcal/kg/d). This emphasizes the need to determine energy expenditure in order to guide nutritional support.